Puzzle Cube Reflection

For the puzzle i created i time a total of five people.

Adult: 15:00 unsolved
High school: 15:00 unsolved
High school: 15:00 unsolved
High school: 15:00 unsolved
Adult: 7:43

Mean: 13.486
Median: 15
Mode: 15
Range: 7.57
Standard Deviation: 3.38541

Questions:
1. Its important to model and design first so you can eliminate as many flaws as possible.
2. The piece i would admire most is the one shaped in the letter P because the letter P is what my name starts with.
3. The one thing i would like to change about my puzzle would be the roughness of the blocks. I really wanted to sand the whole thing down and make it smooth.